This invention relates generally to surgical wound retractors and more specifically to circular wound retractors that provide circumferential retraction of an incision or wound and also provide isolation of the surgical incision or wound from the lumen of the retractor.
Retraction and isolation of a surgical incision can be an important element associated with a surgical procedure. Adequate access may be provided by a circumferential retraction device so that a surgeon may operate in a clear and open, generally unrestricted field. In addition, a circumferential retractor having a fluid impermeable sleeve extending through the incision or wound may prevent excessive bleeding or contamination of adjacent tissue. In some surgeries, it is important to avoid contaminating the incision or wound site.
Common procedures for placing current circumferential wound retraction devices involve placement of an internal retention ring that is coupled to a thin-walled sleeve or tube that is further coupled to an external retention member. The external retention member is wound or turned upon itself to wind the sleeve upon the external retention member. The physics associated with winding a sleeve upon a circular winding collar or external retention member dictate that ample energy must be applied to the external winding motion to provide adequate circumferential retraction of a linear incision. The initial windings of the process are not overwhelming, however, as the process continues the retraction becomes more difficult and the mechanical advantages first appreciated begin to dissipate. The final windings are more difficult since a balance between the force required to wind the sleeve upon the external retention member must be balanced with the force acting to unwind the sleeve from the external retention member.
There remains a need to provide a substantially rigid, noncompliant circumferential retractor that easily shortens the length of an associated tubular sleeve coupled to an internal retention member so that the shortening of the sleeve results in dramatic retraction of an incision or wound. Additionally, the retention members must remain substantially circular so that the incision is retracted symmetrically.